[PATCH v1 1/3] travis-ci: build documentation with AsciiDoc and Asciidoctor

[Lars Schneider <larsxschneider@gmail.com>]

ec3366e introduced a knob to enable the use of Asciidoctor in addition
to AsciiDoc. Build the documentation on TravisCI with this knob to
reduce the likeliness of breaking Asciidoctor support in the future.

Signed-off-by: Lars Schneider <larsxschneider@gmail.com>
---
 .travis.yml              |  2 +-
 ci/test-documentation.sh | 10 +++++++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 591cc57b80..c26f3bf789 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -69,7 +69,7 @@ matrix:
           - asciidoc
           - xmlto
       before_install:
-      before_script:
+      before_script: gem install asciidoctor
       script: ci/test-documentation.sh
       after_failure:
 
diff --git a/ci/test-documentation.sh b/ci/test-documentation.sh
index 579d540d32..e47d2ea611 100755
--- a/ci/test-documentation.sh
+++ b/ci/test-documentation.sh
@@ -7,8 +7,16 @@ set -e
 
 make check-builtins
 make check-docs
-make doc
 
+# Build docs with AsciiDoc
+make doc
 test -s Documentation/git.html
 test -s Documentation/git.xml
 test -s Documentation/git.1
+grep '<meta name="generator" content="AsciiDoc ' Documentation/git.html
+
+# Build docs with AsciiDoctor
+make clean
+make doc USE_ASCIIDOCTOR=1
+test -s Documentation/git.html
+grep '<meta name="generator" content="Asciidoctor ' Documentation/git.html
-- 
2.12.2